Describes the development of a structural model of document retrieval based on lexical-semantic relationships between index terms. An algorithm that uses tree-to-tree distance to measure structural closeness between a document and a query statement is explained, and the proposed model is compared to a vector retrieval model. (18 references) (LRW)

Describes fast, dynamic update algorithms for document retrieval systems. B-trees are discussed; the M-B-T file directory structure is explained; insertions and deletions in inverted files are described; and performance evaluation is discussed. An appendix provides the formal definition of an M-B-T directory. (Contains 18 references.) (LRW)

Presents a modification function for weights of descriptors for documents in fuzzy retrieval systems which includes some desirable properties that are lacking in the model proposed by Choros and Danilowicz in their study on relative indexing. (MBR)

Describes a prototype system for interactive knowledge-based indexing of the medical literature. Topics covered include current indexing practice; knowledge-based systems using frames; various types of assistance provided by the prototype system; and current research activities and plans for the development of the system. (17 references) (CLB)

Presents principles for determining profile of a system user based on analysis of co-occurrence of index terms in queries and pertinent documents. A procedure for determining index term weights, the information value of which depends on the degree of homogeneity of system users, is introduced. Three references are cited. (EJS)

Following a discussion of derivative versus assignment indexing, use of roles, and concept behind Preserved Concept Indexing System, features of PERMDEX (microcomputer program to assist in creation of permuted printed index) are described including indexer input and prompts, the shunting algorithm, and sorting and printing routines. Fourteen…

Presents uniform and efficient approach for processing all truncated query terms in information retrieval which requires one disk access to obtain from the permuted dictionary all strings represented by truncated term. The problem of the overhead storage required to implement the permuted dictionary is discussed. Fifteen references are provided.…

Analyzes the formal properties, structural consequences, similarities, and differences of link indicators, brackets, and cohesion separators in the query languages employed in information retrieval. Eleven figures, a 32-item reference list, and appendices on Extended Backus Notation and the formal definition of the Formal Relevance Language are…

Demonstrates efficiency of preparation of query description using semantic analyser method based on analysis of semantic structure of documents in field of automatic indexing. Results obtained are compared with automatic indexing results performed by traditional methods and results of indexing done by human indexers. Sample terms and codes are…

Proposes a single underlying structure for the production of a variety of computer index displays, using a networking system which represents both concepts and links by nodes. Desirable characteristics of index displays are outlined, and algorithmic extraction of subnetworks for local use is discussed. References are included. (Author/BK)

Discussion of a new method of index term dictionary compression in an inverted-file-oriented database highlights a technique of word coding, which generates short fixed-length codes obtained from the index terms themselves by analysis of monogram and bigram statistical distributions. Substantial savings in communication channel utilization are…

Proposes that topic representations should consist of excerpts from domain thesaurus, generated by spreading activation technique. Algorithm for generating excerpts is outlined and exemplified, and problem of assessing resemblance between two excerpts is discussed. Whether existing thesauri are adequate for this purpose is questioned, and ideas…

Describes the three subsystems of an information retrieval system (document descriptions, queries, and matching algorithms) and argues that the interdependency of these subsystems requires adaptation for the system to perform when any component changes. An algorithm for redescribing documents, in response to changes in queries and retrieval rules,…

Examines through a series of mathematical models (theorems, descriptions, and examples), properties and operations on inverted files, which are used in an information retrieval system based on thesaurus with weighted descriptors. (CWM)

Analyzes the use of weights to denote a query representation and/or the indexing of a document as a generalization of a Boolean retrieval system. Criteria are given for the functions used to evaluate the relevance of the records to a specific query and a new evaluation approach is suggested. (CWM)